The invention provides an asymmetric Au
particle array and FP cavity coupled
refractive index sensor which comprises an insulation substrate, a
metal film reflection layer, a transparent medium layer and a two-dimensional
metal unit array, wherein at least one surface of the insulation substrate is polished; the
metal film reflection layer is deposited on a
polishing surface of the substrate; the transparent medium layer is deposited on the metal film reflection layer; the two-dimensional metal unit array is formed on the transparent medium layer, each metal unit in the two-dimensional metal unit array is an asymmetric unit, and is composed of two metal nano columns arranged along the surface of the substrate, and an F-P cavity loop is formed between the two metal nano columns of each metal unit and the metal film reflection layer just below the two metal nano columns. According to the asymmetric Au
particle array and FP cavity coupled
refractive index sensor, by combining an asymmetric
Fano resonance effect and
coupling an LSP mode and an FP cavity mode, the
full width at half maximum of a
resonance valley of the sensor can be reduced, and thus the performance of a local area surface
plasma sensor is improved.